76GMC1500 said:I had a CDI box go bad on my Yamaha which made the timing run way advanced at idle. But... I would expect some crown damage if timing were the cause of failure. 40:1 oil ratio is pretty lean for a 100 but I don't think that's the problem. Did you happen to measure the bore clearance before you put the new piston in?
Not for sure. But doesn't it mean the chamfering around the bridge between the exhaust ports? Why would the factory original piston do this, especially after running for a few hours previous to the failure? Not trying to argue at all and I really really apreciate all of your help. I am just trying to wrap my head around this whole deal so that I can avoid it from happening again, I really can not afford ($$) to just guess.whenfoxforks-ruled said:Do you know what bridge relief means?
2strokerfun said:With the intake side on the new Wiseco torn up like that, it looks like lack of lubrication to me. Sure someone didn't put unmixed gas in it by mistake??